ezstream is a command line utility which is a improved version of the old
"shout" utility. It enables you to stream mp3 or vorbis files to an icecast
server without reencoding and thus requires very little CPU. ezstream is
controlled via a XML config file (a few examples are provided in the conf
directory).

ezstream can stream mp3, ogg vorbis, and ogg theora files as well as reading
from stdin. ID3v1 tags are supported in mp3 files and all ogg vorbis tags are
propagated as metadata as well.